Polymerization of olefinic hydrocarbons in the presence of boron fluoride and an acid fluoride of a metal



Patented Feb. 18, 1947 POLYMERIZATION OF OLEFINIC HYDRO- -CARBONS IN THE PRESENCE OF BORON AND AN ACID FLUORIDE OF A Carl B. Linn, Riverside, and Vladimir N. I patiei'f, I Chicago, Ill..- assignors to Universal Oil Products Company Chicago, Ill

ware

' 9 Claims. 1

'This invention relates to the polymerization of oleflnic hydrocarbons in the presence of a partlcular type of catalyst. More particularly, this invention relates to the polymerization of ethylene and of other gaseous oleflns into normally liquid hydrocarbons boiling within the approximate range of gasoline.

An object of this invention is to produce normally liquid hydrocarbons by catalytically polymerizing ethylene and higher oleflns.

One specific embodiment of this invention relates to a process which comprises reacting an olefinic hydrocarbon at polymerizing conditions in the presence of boron fluoride and an acid fluoride.

Another embodiment of this invention relates to a polymerization process which comprises reacting a normally gaseous olefin at polymerizing conditions in the presence of boron fluoride and an acid fluoride of an alkali metal.

A further embodiment of this invention relates to a process which comprises polymerizing ethylene 'to normally liquid hydrocarbons in the presence of boron fluoride and an acid fluoride of an alkali metal.

The catalysts hereinafter indicated are especially adapted to promote the controlled polymerization of ethylene and other normally gase- Normally gaseous and liquid oleflnic hydrocarbons which are polymerizable by the process of a corporation oi. Dela- No Drawing. Application March 29, 1945, Serial No. 585,571

2] undergo substantially complete conversion into normally liquid hydrocarbons even at about room temperature in the presence of boron trifluoride and an acid fluoride of an alkali metal such as potassium bifluoride. .This process is also effective for converting propylene and butylenes into normally liquid polymers, and in converting the present invention occur together with paraflinic or saturated. hydrocarbons in commercial hydrocarbon mixtures such as those encountered in the cracking of petroleum, in gas making processes,and as by-products of various chemical industries. Suitable olefins may be obtained also by catalytic dehydrogenation and by pyrolysis of certain parafllnie hydrocarbons. In general, oleflns have a relativelyhigh activity and even under mild catalytic influence they exhibit this activity by their pronounced tendency to polymerize and form substances of higher molecular weights.

It is known that ethylene does not polymerize at moderate. temperature in the presence of pure boron trifluoride. Known promoters for ethylene I polymerization in the presence of boron trifluoride include nickel-powder, water, and hydrogen fluoride. Now we have found that ethylene will range of commercial gasolines.

'amylenes, hexylenes and higher olefins into their dimers, trimers, etc. Propylene and butylenes so polymerized may occur in the gases derived from oilcracking processes or they may be utilized in relatively pure state produced by special means as by the dehydration of alcohols or by the dehydrogenation and fractionation of selected hydrocarbon mixtures; Some polymerization of propylene and butylenes occurs in the presence of pure boron trifluoride. but we prefer to employ boron trifluoride together with an acid fluoride.

The present process is particularly useful for the production of polymers containing from about 6 to about 12 carbon atoms per molecule from ethylene and also from propylene and butylenes. The preferred polymer products boil at temperatures within the approximate boiling These polymers containing from about 6 to about 12 carbon atoms per molecule are useful for blending with straight-run gasoline to increase its antiknock value. 1

Boron trifluoride alone has been used to catalyze the polymerization of isobutylene and other olefinic hydrocarbons at relatively low temperalyst comprising essentially boron 'trifluoride and an acid fluoride of an alkali metal.

While the polymerization reaction of our process occurs rapidly at room temperatures it may also be carried out at a temperature of from about -50 to about 300C. and at a pressure of from about 1 to about 20.0 atmospheres.

At a pressure of 1 atmosphere, boron trifluoride is a colorless gas having a boiling point of hours after addition of all of the ethylene, this Addbfiuoridesgwhicn,are b of charge and recove'redproducts are summarized with borontrifluorideoi o prccess e solidi b h m materials which are neoomoosgogat relatively TABLET high-temperatures into a'r'netal' u'o eeand-hy v drogen fluoride. Acid fluorides which'weprefer..., f m fi f 7 in our process are those of the alkali metals and -Conditionsr, I I II I I include fluorides of lithium, sodium. potassium, 7 Temperature-;'. C 25-35 rubidium, and caesium. The acid fluorides are i gra mfi phresen -"n40- 35-85 sometimes referred to as hydrofluorides or bifluo- I Time, s I

For additionof'czmen urides and are often represented by formulae m I I I I I 4 such as the following: KF-HF, KF'2HF, and Addltional stlrring 12 KF-3HF. In general, the monohydrofiuorldes chargeigramsi are more stable and are therefore preferred as KHFZ I catalyst components, but under proper operating 15 BF3 conditions the dihydrofluorides and trihydrofluorides may be used also. The stabilities of m a the mono-acid fluorides or hydrofiuorides of the BF3 alkali metals decrease in" the -following order: i g sodium, potassium, rubidium, and caesium. 332: 5 1? 31 Therefore. we prefer to use the acid fluorides of sodium and potassium in our process. It will be apparent that the exact range of operating tem eratures and pressures to be employed in the polymerization process will depend somewhat upon the particular acid fluoride which is emp oyed and it should be noted therefore that the various acid fluorides are not necessarily 'on an equivalent basis or utilizable' under exactly The upper layer consisting of liquid hydrocarseparated into fractions with the properties indicated in Table II.

TABLE ll Distillation and properties of ethylene polymerizction product the same conditions of operation. o I I I Our polymerization process may be carried out 5323: B. 1 0. fg am up 3 3 in a batch operation or preferably in continuous operation. The reaction may be carried out con- Below 20 5 d tinuously by passing a mixture of an olefin such 2th -2 0.657 1.3732 0.5 as ethylene and boron trifluoride over a solid acid 35 4 0.5 fluoride contained in a suitable reactor, separat- $3112? ing liquid products, and recycling the recovered .2 1 114242 boron trifiuoride and any unreacted ethylene or ilesidue 338; 11 other olefimc hydrocarbons undergoing treat me'nt. 40

i i (a) This fraction consisted of isobutane as shown by gas analysis. In another type of operation a polymerization reactor may be used comprising a mechanically agitated reaction zone in which finely divided potassium acid fluoride is agitated in the form of a'slurry with the hydrocarbon reactants and boron trifluoride'. It will usually be necessary to incorporate a cooling zone or other heat exchange means in the polymerization zone orbetween such zones if a multiple polymerization reactor system is employed. x

The following example is introduced to illustrate the nature of the present invention as applied to the'polymerization of ethylene. I

A rotatable steel autoclave of 850 cc. capacity The bromine number values given in Table 11 indicate that the lower fractions of the liquid product consisted of substantially'saturated hydrocarbons. Accordingly the reaction by which the ethylene was converted into normally liquid hydrocarbons was largely conjunct polymerization. Some of the fractions of the polymer product, and particularly those of higher boiling point contained a high concentration of cyclic hydrocarbons. The lower boiling fractions, parsuitable for use as motor gasoline while the higher boiling materials which make up a large part of the product have utility as intermediates in the was charged 15 grams of potassium blfluo' manufacture of detergents and other chemical ride. The autoclave was then sealed and 74 igrams of boron trifluoride was added r The novelty and .utility of this invention are The autoclave was rotated and 143 grams of evident from the preceding specification and exethylene was added thereto in 6 approxlmately .ample although neither section is intended to equal batches over a time interval of 4 hours limit undul the generall broad sec of the while the autoclave was maintained at room teminvention y y pe perature. The adsorption of ethylene was rapid We claim as our invention: and although the autoclave was rotated for 12 1. A process which comprises reacting oleflmc hydrocarbons at polymerizing conditions in the additional time of rotation was clearly unnecessary. After the reaction was completed-Etna residual ethylene was released from the autoclavethrough caustic scrubbers, drying towers, collecting traps, and a gas meter. Upon opening the autoclave the reaction product was present in the form of two layers, the lower layer composed of sludge hydrocarbons and catalyst, whilethe upper layer consisted of hydrocarbons.

- The operating conditions and weight balance ticularly those boiling below about C. are.

bons was distilled at atmospheric pressure and presence or boron trifluoride and an acid fluoride presence 01 boron trifluoride and an acid fluoride of an alkali metal.

4. A process for producing normally liquid bydrocarbons which comprises reacting ethylene at polymerizing conditions in the presence of boron trifluoride and an acid fluoride of an alkali metal.

5. A process for polymerizing an oletlnic hydrocarbon which comprises reacting said hydrocarbon at a temperature of from about 50 to about 300 C. in the presence of boron trifluoride and an acid fluoride of a metal.

6. A process for polymerizing an olefinic hydrocarbon which comprises reacting said hydrocarbon at a temperature of from about -50 to about 300 C. in the presence of boron trifluoride and a hydrofluoride'ot an alkali metal.

'7. A process for converting a normally gaseous oleflnic hydrocarbon'into normally liquid hydrocarbons which comprises reacting said olennic hydrocarbon at a temperature of from about -50 to about 300 C. in the presence of boron trlfluoride and a hydrofluoride of an alkali metal.

8. A process for converting ethylene into normally liquid hydrocarbons which comprises reacting ethylene at a temperature of from about to about 300' C. in the presence of boron trifluoride and a hydrofluoride of an alkali metal.

9. A process ,for converting ethylene into normally liquid hydrocarbons which comprises reacting ethylene at a temperature of from about 50 to about 300 C. in the presence of boron trifluoride and potassium bifluoride.

CARL B. LINN. VLADDHR N. IPATEEFT'.

REFERENCES CITED -The following references are of record in the file of this patent:

UNITED STATES PA'I'ENTS Number Name Date 2,085,535 Langediik June 29, 1937 2,186,022 Holm Jan. 9, 1940 2,253,323 Chrlstmann Aug. 19, 1941 2,270,292 Grosse Jan. 20, 1942 2,286,129 Veltman June 9, 1942 2,366,736 Linn et a1. Jan. 9, 1945 

